Theoretical prediction of topological insulator in ternary rare earth chalcogenides

TL;DR

This paper theoretically predicts a new class of three-dimensional topological insulators, specifically ternary rare earth chalcogenides, using ab initio calculations, and explores their potential for novel topological states and applications.

Contribution

It introduces ternary rare earth chalcogenides as a new class of topological insulators and predicts their properties and potential for hosting various topological states.

Findings

LaBiTe3 is a topological insulator.

YBiTe3 and YSbTe3 are normal insulators.

Rare earth substitution can lead to novel topological states.

Abstract

A new class of three-dimensional topological insulator, ternary rare earth chalcogenides, is theoretically investigated with ab initio calculations. Based on both bulk band structure analysis and the direct calculation of topological surface states, we demonstrate that LaBiTe3 is a topological insulator. La can be substituted by other rare earth elements, which provide candidates for novel topological states such as quantum anomalous Hall insulator, axionic insulator and topological Kondo insulator. Moreover, YBiTe3 and YSbTe3 are found to be normal insulators. They can be used as protecting barrier materials for both LaBiTe3 and Bi2Te3 families of topological insulators for their well matched lattice constants and chemical composition.